Rogers J R, Harvey R W, Poore M H, Mueller J P, Barker J C
Department of Animal Science, North Carolina State University, Raleigh 27695-7621, USA.
J Anim Sci. 1996 May;74(5):1126-33. doi: 10.2527/1996.7451126x.
A 2-yr study was conducted to evaluate 1) the effects of nitrogen level from swine lagoon effluent on forage composition and animal performance and 2) the effects of supplemental escape protein (EP) on performance by steers grazing pastures fertilized with swine lagoon effluent. Bermudagrass (Cynodon dactylon) pastures were fertilized via sprinkler irrigation with either 448 or 896 kg/ha of N from swine lagoon effluent (two pasture replications/treatment). Within each pasture, four supplement treatments were evaluated using electronic Calan gates (8 steers.pasture-1.yr-1). The treatments were 1) negative control (pasture only); 2) energy control, which supplied 79.9 g of EP.hd-1.d-1; 3) 159 g of EP.hd-1.d-1, and 4) 239 g of EP.hd-1.d-1. Gains were increased (P < .05) an average of .15 kg/d by supplementation, with no differences in gain among supplements. Forage samples representative of that grazed by steers (CONSUM) and representative of all available forage (AVAIL) were obtained at 14-d intervals. Total CP content of CONSUM and AVAIL samples were slightly higher (P < .20 and P < .15, respectively) from pastures fertilized with 896 compared with 448 kg/ha of N (20.8 vs 20.0% for CONSUM and 15.2 vs 14.2% for AVAIL). Concentrations of nonprotein N and soluble true protein (% of CP) in both AVAIL and CONSUM samples were higher (P < .06) from pastures fertilized with the higher N level. Total N uptake by the plant, based on CP content and animal grazing days/ha, was essentially the same for both N treatments.
开展了一项为期两年的研究，以评估：1）猪场废水氮水平对牧草组成和动物生产性能的影响；2）补充逃逸蛋白（EP）对放牧于用猪场废水施肥的牧场的阉公牛生产性能的影响。通过喷灌向狗牙根（Cynodon dactylon）牧场施用448或896千克/公顷来自猪场废水的氮（每个处理两个牧场重复）。在每个牧场内，使用电子卡兰门评估四种补充处理（每个牧场每年8头阉公牛）。处理分别为：1）阴性对照（仅牧场）；2）能量对照，提供79.9克EP/头·天；3）159克EP/头·天；4）239克EP/头·天。补充营养使日增重平均提高了0.15千克（P < 0.05），各补充处理间增重无差异。每隔14天采集代表阉公牛采食的牧草样本（CONSUM）和所有可利用牧草的样本（AVAIL）。与施用448千克/公顷氮的牧场相比，施用896千克/公顷氮的牧场中，CONSUM和AVAIL样本的总粗蛋白含量略高（分别为P < 0.20和P < 0.15）（CONSUM样本为20.8%对20.0%，AVAIL样本为15.2%对14.2%）。施用较高氮水平的牧场中，AVAIL和CONSUM样本中的非蛋白氮和可溶性真蛋白浓度（占粗蛋白的百分比）更高（P < 0.06）。基于粗蛋白含量和动物每公顷放牧天数，两种氮处理下植物的总氮吸收量基本相同。
